I'm having trouble with my 04 Accord EX, 4 cylinder. The CEL came on yesterday and it's giving me code P2647, which I know is the oil pressure switch.

I got the same CEL back in December at ~95K miles and replaced the lower oil pressure switch (PN 37240-P2F-A01). Problem fixed.

I'm now at ~108K miles and I got the same code yesterday.

Questions:
1. There are two oil pressure switches. Does the other one (not at the oil filter) throw a different code?

2. If it's the same code... how do you know which is the problem.

3. Assuming it's the same one again... what could have caused it to fail after 6 months and 13K miles?

Thanks,
Scott